Preventing Identity Attacks in RFID Backscatter Communication Systems: a Physical-Layer Approach

This work considers identity attack on a radio-frequency identification (RFID)-based backscatter communication system. Specifically, we consider a singlereader, single-tag RFID system whereby the reader and the tag undergo two-way signaling which enables the reader to extract the tag ID in order to authenticate the legitimate tag (L-tag). We then consider a scenario whereby a malicious tag (M-tag)—having the same ID as the Ltag programmed in its memory by a wizard—attempts to deceive the reader by pretending to be the L-tag. To this end, we counter the identity attack by exploiting the non-reciprocity of the end-to-end channel (i.e., the residual channel) between the reader and the tag as the fingerprint of the tag. The passive nature of the tag(s) (and thus, lack of any computational platform at the tag) implies that the proposed light-weight physical-layer authentication method is implemented at the reader. To be concrete, in our proposed scheme, the reader acquires the raw data via two-way (challenge-response) message exchange mechanism, does least-squares estimation to extract the fingerprint, and does binary hypothesis testing to do authentication. We also provide closed-form expressions for the two error probabilities of interest (i.e., false alarm and missed detection). Simulation results attest to the efficacy of the proposed method

Left-m-filter, Right-n-filter and (m,n)-filter on Ordered Semigroup

In this paper, as a generalization of the concepts of left filters, right filters and filters of ordered semigroups, the concepts, for any positive integers m and n, of left-m-filters, right-n-filters and $(m,n)$ -filters in ordered semigroups have been introduced and some properties of these generalized notions have been investigated. Finally left-m-filters (resp. right-n-filters, $(m,n)$ -filters) of $(m,0)$ -regular (resp. $(0,n)$ -regular, $(m,n)$ -regular) ordered semigroups have been characterized in terms of its prime generalized $(m,0)$ -ideals (resp. $(0,n)$ -ideals, $(m,n)$ -ideals)

Generalized fuzzy Gamma-ideals of ordered Gamma-semigroups

<p>In this paper, the notions of (∈, ∈ ∨(k ∗, qk))-fuzzy left Γ-ideals, (∈, ∈ ∨(k ∗, qk))-fuzzy right Γ-ideals and (∈, ∈ ∨(k ∗, qk))-fuzzy Γ-ideals in ordered Γ-semigroups are introduced and their related properties are investigated. Furthermore, (k ∗, k)-lower parts of (∈, ∈ ∨(k ∗, qk))-fuzzy left Γ-ideals, (∈, ∈ ∨(k ∗, qk))-fuzzy right Γ-ideals and (∈, ∈ ∨(k ∗, qk))-fuzzy Γ-ideals are also defined. Finally, left regular, right regular and regular ordered Γ-semigroups in terms of (∈, ∈ ∨(k ∗, qk))-fuzzy left Γ-ideals and (∈, ∈ ∨(k ∗, qk))-fuzzy right Γ-ideals are characterized. </p&gt

Investigating Snow Cover and Hydrometeorological Trends in Contrasting Hydrological Regimes of the Upper Indus Basin

The Upper Indus basin (UIB) is characterized by contrasting hydrometeorological behaviors; therefore, it has become pertinent to understand hydrometeorological trends at the sub-watershed level. Many studies have investigated the snow cover and hydrometeorological modeling at basin level but none have reported the spatial variability of trends and their magnitude at a sub-basin level. This study was conducted to analyze the trends in the contrasting hydrological regimes of the snow and glacier-fed river catchments of the Hunza and Astore sub-basins of the UIB. Mann-Kendall and Sen’s slope methods were used to study the main trends and their magnitude using MODIS snow cover information (2001–2015) and hydrometeorological data. The results showed that in the Hunza basin, the river discharge and temperature were significantly (p ≤ 0.05) decreased with a Sen’s slope value of −2.541 m3·s−1·year−1 and −0.034 °C·year−1, respectively, while precipitation data showed a non-significant (p ≥ 0.05) increasing trend with a Sen’s slope value of 0.023 mm·year−1. In the Astore basin, the river discharge and precipitation are increasing significantly (p ≤ 0.05) with a Sen’s slope value of 1.039 m3·s−1·year−1 and 0.192 mm·year−1, respectively. The snow cover analysis results suggest that the Western Himalayas (the Astore basin) had a stable trend with a Sen’s slope of 0.07% year−1 and the Central Karakoram region (the Hunza River basin) shows a slightly increasing trend with a Sen’s slope of 0.394% year−1. Based on the results of this study it can be concluded that since both sub-basins are influenced by different climatological systems (monsoon and westerly), the results of those studies that treat the Upper Indus basin as one unit in hydrometeorological modeling should be used with caution. Furthermore, it is suggested that similar studies at the sub-basin level of the UIB will help in a better understanding of the Karakoram anomaly

Characterizations of Regular Ordered Semigroups by (∈,∈∨(<i>k</i>^∗,<i>q_k</i>))-Fuzzy Quasi-Ideals

In this paper, some properties of the ( k &#8727; , k ) -lower part of ( &#8712; , &#8712; &or; ( k &#8727; , q k ) ) -fuzzy quasi-ideals are obtained. Then, we characterize regular ordered semigroups in terms of its ( &#8712; , &#8712; &or; ( k &#8727; , q k ) ) -fuzzy quasi-ideals, ( &#8712; , &#8712; &or; ( k &#8727; , q k ) ) -fuzzy generalized bi-ideals, ( &#8712; , &#8712; &or; ( k &#8727; , q k ) ) -fuzzy left ideals and ( &#8712; , &#8712; &or; ( k &#8727; , q k ) ) -fuzzy right ideals, and an equivalent condition for ( &#8712; , &#8712; &or; ( k &#8727; , q k ) ) -fuzzy left (resp. right) ideals is obtained. Finally, the existence theorems for an ( &#8712; , &#8712; &or; ( k &#8727; , q k ) ) -fuzzy quasi-ideal as well as for the minimality of an ( &#8712; , &#8712; &or; ( k &#8727; , q k ) ) -fuzzy quasi-ideal of an ordered semigroup are provided

Communication of Sensor Data in Underground Mining Environments: An Evaluation of Wireless Signal Quality over Distance

The technologies of the fourth industrial revolution have the potential to make zero harm possible for the first time in the history of mining. In the journey toward zero harm, rock stress monitoring systems are important for the risk management process. Although communication systems for underground mining have improved significantly over the past two decades, it remains difficult to achieve reliable-all-the-time wireless communication in ultra-deep level underground mines. The aim of this study is to explore and test a smart phone network for communicating sensor data from the underground production environment to the surface. In this paper, the evaluation and performance over distance of a wireless communication system is performed in underground mining environments. The wireless system transmits the data collected from a sensor installed in a narrow reef stope, horizontal tunnel, and vertical shaft area of a mock underground mine. The evaluation was performed using the received signal strength of a mobile receiver over distance. The path loss coefficients of the underground mining environment were then derived for the measurement areas. The results show that a communication speed of 80 Mbps was achieved in a 60 m range, thus, indicating the potential for the support of applications requiring higher data rates

On New Filters in Ordered Semigroups

Ordered semigroups are understood through their subsets. The aim of this article is to study ordered semigroups through some new substructures. In this regard, quasi-filters and (m,n)-quasi-filters of ordered semigroups are introduced as new types of filters. Some properties of the new concepts are investigated, different examples are constructed, and the relations between quasi-filters and quasi-ideals as well as between (m,n)-quasi-filters and (m,n)-quasi-ideals are discussed

Linear Diophantine Fuzzy Set Theory Applied to <i>BCK/BCI</i>-Algebras

In this paper, we apply the concept of linear Diophantine fuzzy sets in BCK/BCI-algebras. In this respect, the notions of linear Diophantine fuzzy subalgebras and linear Diophantine fuzzy (commutative) ideals are introduced and some vital properties are discussed. Additionally, characterizations of linear Diophantine fuzzy subalgebras and linear Diophantine fuzzy (commutative) ideals are considered. Moreover, the associated results for linear Diophantine fuzzy subalgebras, linear Diophantine fuzzy ideals and linear Diophantine fuzzy commutative ideals are obtained